Effects of a naturally occurring neurosteroid on GABAA IPSCs during development in rat hippocampal or cerebellar slices - PubMed (original) (raw)

Overlay of averaged mIPSCs of (from left to right) HG10, HG20 and CP20 cells (n > 50) at progressively increasing concentrations (control, 0.05, 0.1, 1.0, 2.0 μ

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) of THDOC indicates the dose-dependent potentiating effect of THDOC. Note the lack of effect of 50 or 100 n

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THDOC in the HG20 cell. Concentrations of THDOC are indicated on the right, amplitudes are scaled for comparison of decays. B, dose-response curve for THDOC effect on the time constant of the second exponential fitted to the decay time of mIPSCs (τ2). Note the difference in scale for the _y_-axis between CP cells and HG cells. The potentiation is considerably greater in Purkinje cells but this is due to a faster decay of control currents (Table 1). ○, 10 day group (HG10 n = 7, CP10 n = 3); •, 20 day group (HG20 n = 5, CP20 n = 5); in CP10 cells the time constants for single exponential fits (τ) and τ2 for averaged currents fitted with two exponentials are combined. Note that not all cells were exposed to 2 μ

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THDOC and hence these points represent 2 of 7 HG10 cells, 4 of 5 HG20 cells, 3 of 3 CP10 cells and 3 of 5 CP20 cells. C, effects of lower (possibly physiological) concentrations of THDOC (50 and 100 n

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) reveal a developmental change in HG cells. Note there is considerable variation between cells, particularly in the HG10 group as detailed in the text. *P < 0.05; **P < 0.01, one-way ANOVA. HG10, n = 11; HG20, n = 17; CP10, n = 7; CP20, n = 4; CG10, n = 4.